EVANSTON (Sun-Times Media Wire) - A shooting scare shut down Northwestern University’s Evanston campus Wednesday afternoon when someone called police claiming he had opened fire inside a graduate residence hall, in a bogus report that authorities have deemed a “swatting” incident, the Chicago Sun-Times is reporting.

Evanston police received a call at 2:17 p.m. from a person who said he had shot his girlfriend inside an apartment at Englehart Hall, 1915 Maple Ave., about three blocks west of the main campus, according to Evanston Police Cmdr. Ryan Glew.

The call drew a massive police response, but officers found no one hurt or any evidence of a shooting. Officials soon determined that the unit where the shooting supposedly happened has been vacant since last November, and the call was traced to an area southeast of Rockford.

“It is a hoax,” Glew said.

The university first issued an alert at 2:39 p.m. warning anyone on campus to seek shelter, and urging others to stay away from the campus.

But Aiden Hartmann found out while working the front desk of the residence hall.

“I saw a cop car pull up and an officer got out with a gun. Then another pulled up with a bigger gun,” Hartmann said. “I was freaked out.”

Hartmann and another worker locked themselves in a bathroom for two hours, following updates on their phones.

Will Ewing, an Englehart resident, was walking toward the building’s back entrance when a handful of heavily armed officers told him to “Get back!” He waited out the investigation at a bakery in downtown Evanston.

“All my classmates were messaging each other to make sure we were OK,” Ewing said. “Teachers were pushing couches up against their doors.”

Colin Boyle ran toward the scene with his camera to snap photos for NU’s student newspaper, The Daily Northwestern. Boyle said he texted his family members to let him know he was all right.

“My mother was hysterical,” he said.

Boyle and other students lauded the steady stream of updates from the school via text alerts, emails and automated phone calls. The lockdown was lifted by 4:15 p.m.

“This is the sort of thing that is a nightmare to a university,” NU spokesman Alan Cubbage said.

The caller claimed to have shot a woman who is a student, officials said. Authorities tracked her down and she was safe. It wasn’t clear if she had ever lived in the apartment or knew the caller.

Glew called it a “swatting” incident — a false report intended to provoke a SWAT team response, sometimes to divert police attention away from other crimes. No other incidents were reported on campus Wednesday afternoon, Cubbage said.